AutoCodes – Generic – P284B

P284B Code - Shift Fork 'C' Stuck

Quick Answer

There are two electric motors used to shift the gears in the transmission, on for gears 1-3-5 and one for gears R-2-4-6. Common causes include Outdated Transmission Control Module (TCM) program (Reprogram TCM), Faulty Transmission Control Module (TCM), Faulty Transmission Assembly. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P284B indicates Shift Fork 'C' Stuck.
Common causes: Common causes include Outdated Transmission Control Module (TCM) program (Reprogram TCM), Faulty Transmission Control Module (TCM), Faulty Transmission Assembly.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 16,513

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Feb 16, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P284B Description

There are two electric motors used to shift the gears in the transmission, on for gears 1-3-5 and one for gears R-2-4-6. The gear shifting is made by two shift drums connected to shift motor pinion via two ideal gears. The maximum shift force is 1500N (337 lb). The motors are integrated in the Transmission Control Module (TCM) and work independently of each other.

OBDII Code P284B - Shift Fork 'C' Stuck - AutoCodes.com — P284B Code - Shift Fork 'C' Stuck

What does this mean?

What are the Possible Causes of the DTC P284B?

Outdated Transmission Control Module (TCM) program (Reprogram TCM)
Faulty Transmission Control Module (TCM)
Faulty Transmission Assembly

How to Fix the DTC P284B?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P284B code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P284B code?

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Need Help with the Code?

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Information for Specific Makes

P284B Ford — Shift Fork 'C' Stuck
P284B Nissan — Shift Fork 'C' Stuck

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.